Study of Visual Evoked Potentials in Schoolchildren: A Promising Aid to Pediatric Ophthalmology.

Background Visual evoked potential (VEP) is a noninvasive investigation conducted to identify abnormalities in the visual system. It is especially suitable for young children who are unable to express visual symptoms or participate in conventional vision tests. This study was undertaken to examine the VEP among schoolchildren to assess the functionality of their optic pathway. Methodology This short-term observational study was performed in the Clinical Neurophysiology Unit of the Physiology Department of a rural medical college. The study population consisted of 60 schoolchildren aged 7-12. Both eyes were examined for transient pattern reversal VEP recordings using a Recorders & Medicare Systems Electromyography-Evoked Potential recorder (RMS EMG-EP MARK-II Pvt. Ltd., Chandigarh, India). Results VEPs were analyzed for latency and amplitude of the main components, namely P100, N70, and N155. The results showed markedly extended P100 latency in 33.33%, i.e., eight out of 24 eyes of standard (std.) III children. Similar latency prolongation was obtained in 36.36% (eight out of 22) eyes of std. IV, 30% (six of 20 eyes) of std. V, 13.63% (three of 22 eyes) of std. VI, and 50% (eight of 16 eyes) in std. VII and VIII children. A markedly reduced P100 amplitude was observed in two of 20 eyes (10%) of std. V, two of 16 eyes (12.5%) in std. VII and VIII children, amounting to a P100 amplitude abnormality in 5% eyes in toto. The interocular differences in all VEP parameters among the subjects were statistically insignificant. Conclusion In schoolchildren in whom normal latencies and amplitudes were obtained, the presence of reproducible VEPs indicated the normal functional status of their visual pathway. On the other hand, in those children where altered VEP findings were found, it hinted toward complementary information that they may have underlying ocular disorders that were yet to be diagnosed. Hence, this study provides insight into the assessment of visual system function, which is primarily difficult in young children.